1. Technical Field
The present invention relates to a travel control apparatus for a vehicle that performs automatic driving control by recognizing a travel environment and detecting travel information relating to the vehicle.
2. Related Art
Recently, various travel control apparatuses using automatic driving technology have been developed and proposed with the aim of allowing a driver to drive a vehicle in increased comfort. In this type of travel control apparatus, various types of travel control (for example, following control relative to a preceding vehicle, lane keep control, lane deviation prevention control, overtaking control relative to a preceding vehicle, and so on) for the purpose of automatic driving can be performed by detecting the travel environment of the vehicle through recognition of the travel environment on the exterior of the vehicle using various recognition devices employing a camera, a laser radar, a millimeter wave radar, an ultrasonic sonar, and so on.
When a driver intervenes in (overrides) the automatic driving performed by this type of travel control apparatus by executing a predetermined driving operation, the will of the driver, expressed through the driving operation, is preferably reflected appropriately in the travel control. In response to this requirement, Japanese Unexamined Patent Application Publication (JP-A) No. H10-194150, for example, discloses a technique for determining that an emergency operation (an intervening driving operation) has been performed in order to avoid danger and switching forcibly to a manual steering mode when, during automatic steering, a torque (a steering torque) detected by a steering torque sensor exceeds a predetermined value or a brake operation is detected by a brake sensor.